George Smyris

The historical bridge of Plaka, built in 1866, collapsed in 2015 due to foundation failure, during a heavy rainfall. It was considered as the largest single-arched stone bridge of the Balkans, with the main arch having ~40m diameter. The bridge was constructed with local materials and techniques. It is important to be noted that due to the collapse, it was possible to detect the whole structural system and observe for the first time construction details and reinforcements (timber and metal) that were not known until now, never detected in other bridges nor mentioned in the relevant bibliography. A unique system of hidden timber reinforcements was discovered unexpectedly in the interior mass of the stone structure, when the stone parts of the bridge fell into the river. Two types of timber grids were revealed at the central arch. The 1 st type was placed in specific distances radially, in between the cut stones of the double central arch of the bridge. At the same positions, a 2 nd type of timber grid existed, running almost horizontally at the main mass of the piers. The 3 rd timber reinforcement system was placed transversely along the small West and East arches of the bridge. Finally, two types of metal reinforcements were used. A visible one, placed transversely at the inner central arch, a common technique used in most stone bridges in Greece, and another one, unknown too until the collapse, a grid of metal straps placed horizontally in different layers, hidden at the lower underwater part of the bridge pillars, connecting the stones near the foundation with special lead details for its anchorage.

The University as an academic institution, beyond its primary goal of new knowledge construction and high quality education, must have close connections with and contribute to society. This is even more important for a peripheral institution and especially for the University of Ioannina which is located in western Greece, an area with a great tradition in culture and a crucial geographical location.

The historical bridge of Plaka, built in 1866, collapsed in 2015 due to foundation failure, during a heavy rainfall. It was considered as the largest single-arched stone bridge of the Balkans, with the main arch having ~40m diameter. The bridge was constructed with local materials and techniques. It is important to be noted that due to the collapse, it was possible to detect the whole structural system and observe for the first time construction details and reinforcements (timber and metal) that were not known until now, never detected in other bridges nor mentioned in the relevant bibliography. A unique system of hidden timber reinforcements was discovered unexpectedly in the interior mass of the stone structure, when the stone parts of the bridge fell into the river.  Finally, two types of metal reinforcements were used. A visible one, placed transversely at the inner central arch, a common technique used in most stone bridges in Greece, and another one, unknown too until the collapse, a grid of metal straps placed horizontally in different layers, hidden at the lower underwater part of the bridge pillars, connecting the stones near the foundation with special lead details for its anchorage.